HONG KONG, Jan 29 (Reuters) - Hong Kong’s Exchange Fund, which is used to back the Hong Kong dollar, posted a record investment income of HK$252 billion ($32.23 billion) in 2017, the Hong Kong Monetary Authority (HKMA) said on Monday.

The figure compared with an adjusted HK$68.13 billion investment gain in 2016.

That compared with an adjusted investment income of HK$61.8 billion in the third quarter, HK$71.3 billion in the second quarter and HK$64.9 billion in the first, HKMA said.

The HKMA is the key manager of the Exchange Fund, which is under the control of the financial secretary and invests in equities, bonds, foreign exchange and other securities and assets.